I’ve been experimenting further with powering paper bellows. I’d already tried fitting a set of bellows into a scotch yoke mechanism, this time I’ve tried a slightly simpler mechanism. I’ve fitted a bellow (s?) at each end of a tube then connected them both to a crank.

Here it is in action on my Instagram account. Looking (and sounding) good!

Here’s something a little more ambitious. A radial engine, of the type used to drive aeroplane propellors but with bellows where the cylinders are and various pitches of pipes. Now that could be a fun project!